package com.ht.util;

import cn.hutool.core.util.StrUtil;
import lombok.extern.slf4j.Slf4j;
import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;


/**
 * ip工具类
 * @author hejialun
 * @since 2021/4/22 15:30
 */
@Slf4j
public class IPUtils {

	private static final String IP_UTILS_FLAG = ",";
	private static final String UNKNOWN = "unknown";
	private static final String LOCALHOST_IP = "0:0:0:0:0:0:0:1";
	private static final String LOCALHOST_IP1 = "127.0.0.1";

	/**
	 * 获取IP地址
	 * <p>
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr(HttpServletRequest request) {
		String ip = "127.0.0.1";
		try {
			try {
				//以下两个获取在k8s中，将真实的客户端IP，放到了x-Original-Forwarded-For。而将WAF的回源地址放到了 x-Forwarded-For了。
				ip = request.getHeader("X-Original-Forwarded-For");
				if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getHeader("X-Forwarded-For");
				}
				//获取nginx等代理的ip
				if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getHeader("x-forwarded-for");
				}
				if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getHeader("Proxy-Client-IP");
				}
				if (StrUtil.isEmpty(ip) || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getHeader("WL-Proxy-Client-IP");
				}
				if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getHeader("HTTP_CLIENT_IP");
				}
				if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getHeader("HTTP_X_FORWARDED_FOR");
				}
				//兼容k8s集群获取ip
				if (StrUtil.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
					ip = request.getRemoteAddr();
					if (LOCALHOST_IP1.equalsIgnoreCase(ip) || LOCALHOST_IP.equalsIgnoreCase(ip)) {
						//根据网卡取本机配置的IP
						InetAddress iNet = null;
						try {
							iNet = InetAddress.getLocalHost();
						} catch (UnknownHostException e) {
							log.error("getClientIp error: {}", e);
						}
						ip = iNet.getHostAddress();
					}
				}
			} catch (Exception e) {
				log.error("IPUtils ERROR ", e);
			}
			//使用代理，则获取第一个IP地址
			if (!StrUtil.isEmpty(ip) && ip.indexOf(IP_UTILS_FLAG) > 0) {
				ip = ip.substring(0, ip.indexOf(IP_UTILS_FLAG));
			}
		} catch (Exception e) {
			log.error("IPUtils ERROR ", e);
		}
		return ip;
	}
}